The US is pushing for a dangerously broad definition of a criminal violation of copyright, where even noncommercial activities could get people convicted of a crime. The leak also shows that Canada has opposed this definition. Canada supports language in which criminal remedies would only apply to cases where someone infringed explicitly for commercial purposes.
This distinction is crucial. Commercial infringement, where an infringer sells unauthorized copies of content for financial gain, is and should be a crime. But that's not what the US is pushing for—it's trying to get language passed in TPP that would make a criminal out of anyone who simply shares or otherwise makes available copyrighted works on a “commercial scale.”
As anyone who has ever had a meme go viral knows, it is very easy to distribute content on a commercial scale online, even without it being a money-making operation. That means fans who distribute subtitles to foreign movies or anime, or archivists and librarians who preserve and upload old books, videos, games, or music, could go to jail or face huge fines for their work. Someone who makes a remix film and puts it online could be under threat. Such a broad definition is ripe for abuse, and we've seen such abuse happen many times before.